We can trace the beginning of beer drinking far back beyond the dawn of recorded time. Most likely, a crude form of beer was discovered by accident when someone mixed barley with water and then let it sit long enough for stray yeast cells to settle, triggering fermentation. The Babylonians, Assyrians, Egyptians, Hebrews, Africans, Chinese, Incas, Teutons, Saxons and various wandering tribes all discovered beer by various independent means. The dispensing system used by these early brewers were amphora, mugs and the early equivalent of straws, which were used to sip the liquid beer while avoiding the brewer's residue.
From the middle ages, when the use of hops made beer clear, until the 1890's, beer was stored in and dispensed from wooden barrels through simple valves and delivered to the drinker mug or glass by gravity flow. From the 1950's to the present most draft beer has been shipped in and dispensed from kegs that are cylindrical, made of stainless steel or aluminum and contain an extractor tube.
To dispense the beer from the keg a pressurizing gas, air or CO2, is forced into the keg through a beer keg tap. The liquid beer is forced out through the extractor tube, flexible hoses and a delivery faucet. Air is very undesirable as a pressurizing gas because the oxygen in air makes beer quickly go stale or sour. Air can be used when the entire keg is to be drunk quickly. Air cannot be used as a pressurizing gas if the keg must be stored and the beer consumed over a period of time.
There are two general types of beer dispensing systems taught by the prior art. One is a commercial system that uses heavy pressure bottles of compressed carbon dioxide gas operating through regulators and pressure lines to pressurize one or more kegs. The other is a consumer system usually used at a party or picnic that uses an air pump, which may be a hand powered or electrically operated compressor, to pressurize the keg. This is therefore commonly known as a picnic pump system.
Advantages of the commercial beer dispensing systems include the use of CO2 dispensing systems that prevent air from coming in contact with the keg beer and thus allowing the keg beer to stay fresh for a longer period of time than when air is used as a pressurizing gas. Another advantage of a commercial beer dispensing system is the ability to control the pressure of the gas supplied to the keg through the use of adjustable regulators and pressure gauges. This feature is a marked advantage over a picnic pump system as it allows the pressure to be finely tuned to the individual type of beer or the specific temperature of the keg to prevent excessive foaming of the dispensed beer as is often encountered in the picnic pump systems.
Examples of commercial beer dispensing systems may be found in most bars and restaurants. This equipment is cumbersome and industrial. Their ‘rat's nest’ of tubing is a common feature behind bars. These commercial CO2 dispensing systems weigh hundreds of pounds and can operate dozens of beer keg taps and draft beer dispensers. This equipment is completely unsuitable for use at picnics, parties or for the large and growing number of drinkers who wish to keep a keg of beer at home in their refrigerator so they can have draft beer at home on demand.
Picnic pumps such as the one taught by U.S. Pat. No. 4,711,377, issued to Brown on Dec. 8, 1987 use a hand-operated air pump. Such pumps are common and exist in hundreds of variations. These pumps are small and lightweight, but they pressurize the beer keg with air, which makes them unsuitable for use with a home keg because contact with the oxygen in air quickly ruins the beer.
U.S. Pat. No. 5,785,211 teaches a portable electrically powered keg-tapping device for use with regular beer kegs. The electrical compressor is a good replacement for a hand pump, but it does not solve the problem of introducing air into a keg that must be stored and used over a period of time.
An advantageous beer pumping system would combine the beer preservation and adjustable pressurization available with commercial type systems with the low profile and portability of a picnic pump system. Portable beer dispensing systems, such as the one taught by U.S. Pat. No. 5,199,609, issued to Ash on Apr. 6, 1993, teach the use of a CO2 bottle packaged in a backpack and connected by pressure tubes to a container of beer. This type of dispenser, and there are many examples in the prior art, is useful for dispensing beer at sporting events, but uses a special small beer tank and thus cannot be of any use to home beer keg owners.
Another portable beer dispensing system, U.S. Pat. No. 2,571,433, issued to Fine et al. on Oct. 16, 1951, teaches the use of a small pressurized cylinder and a regulator permanently attached to a specialized beer container. However, the specialized beer container is not commercially available. Furthermore the pressurization system is permanently attached to the non commercially available specialized beer container. Additionally, the presence of a cover over the pressurization system does not facilitate precision pressure adjustments for individual types of beer or specific keg temperatures to prevent unwanted foaming. A more useful device will combine all the advantages of a commercial beer pumping system, such as CO2 pressurization to maintain beer freshness and easy adjustability of the CO2 pressure to prevent foaming, with the low profile and portability of a picnic pump system. Interestingly, no devices that incorporate all the advantages of a commercial beer pumping system with the low profile and portability of a picnic beer pumping system currently exist.
This combination would allow for a simple home draft beer system by placing a small, easily adjustable CO2 pressurized beer pump on any commercially available beer keg. The keg with the beer pump could then be placed in any conventional refrigerator for to keep the beer at a constant drinkable temperature. Currently, home kegs may be kept in refrigerated one keg systems, such as the Beer Baron® sold by Ajex USA, Inc. of Commerce City, Colo., but such “home” draft beer systems are huge, weigh several hundred pounds and are very expensive.
U.S. Pat. No. 4,180,189, issued to Zurit et al. Dec. 25, 1979 teaches the use of a standard keg tap using a conventional bayonet type of connection to attach the tap to the keg. In addition U.S. Pat. No. 4,180,189 also teaches the use of a pressure inlet to pressurize the beer keg in combination with a Thomas valve designed to prevent back pressure or beer from flowing out of the pressure inlet into the pressure producing source. However, the incorporation of a Thomas valve to help prevent back pressure or beer into the pressure producing has not been rigidly attached to a regulator and a rigidly attached gas canister designed for kegs to be stored in a home refrigerator. The Thomas valve in U.S. Pat. No. 4,180,198 would be designed to prevent back pressure or beer from flowing into a flexible tube used to deliver pressure to the tap, thereby preventing damage to the flexible tube. A desirable invention, in combining all the advantages of a commercial beer pumping system with the low profile and portability of a picnic beer pumping system would have a Thomas valve directly attached to a check valve and furthermore to an easily adjustable pressure regulator and finally attached to a pressurized CO2 canister.
It is applicant's belief that none of the above prior art systems have received commercial recognition because they either are too expensive to construct, or are not reliable. None of the above prior art systems solve the problems facing the home keg owner who wishes to tap the keg and still keep the beer fresh over an extended period.